Answer:
x=amount invested at 7%
2x=amount invested at 8%
3x=amount invested at 9%
interest=principal*rate*time (time=1 year)
$150=0.07x+0.08*2x+0.09*3x
$150=0.07x+0.16x+0.27x
$150=0.50x
$1500=5x
x=$300 invested at 7%
2x=$600 invested at 8%
3x=$900 invested at 9%
Step-by-step explanation:
it is 11.25................................
Answer:
the answer is 10
Step-by-step explanation:
(8+4+14+16+8)/5
Ya, calculus and related rates, such fun!
everything is changing with respect to t
altitude rate will be dh/dt and that is 1cm/min
dh/dt=1cm/min
area will be da/dt which is increasing at 2cm²/min
da/dt=2cm²/min
base=db/dt
alright
area=1/2bh
take dervitivie of both sides
da/dt=1/2((db/dt)(h)+(dh/dt)(b))
solve for db/dt
distribute
da/dt=1/2(db/dt)(h)+1/2(dh/dt)(b)
move
da/dt-1/2(dh/dt)(b)=1/2(db/dt)(h)
times 2 both sides
2da/dt-(dh/dt)(b)=(db/dt)(h)
divide by h
(2da/dt-(dh/dt)(b))/h=db/dt
ok
we know
height=10
area=100
so
a=1/2bh
100=1/2b10
100=5b
20=b
so
h=10
b=20
da/dt=2cm²/min
dh/dt=1cm/min
therefor
(2(2cm²/min)-(1cm/min)(20cm))/10cm=db/dt
(4cm²/min-20cm²/min)/10cm=db/dt
(-16cm²/min)/10cm=db/dt
-1.6cm/min=db/dt
the base is decreasing at 1.6cm/min
